All characters are generally displayed on the same touch panel, in electric device having a character input function using a touch panel. For example, in an alphabet, all twenty-six characters thereof are displayed on the same touch panel, and in “kana characters (hiragana)” which are Japanese characters, all forty-six characters thereof are displayed on the same touch panel. The touch panel has both a function as a display displaying characters and a function as a touch sensor detecting contact.
In mobile electronic device, like a mobile phone and a PDA (Personal Data Assistance), a character display unit and a character input unit are limited in size, due to the nature of the mobile electronic device. It is, therefore, difficult to secure an area on which many characters are displayed and on which a character to be inputted can be selected in the characters. For example, if the display and the touch panel for character input are arranged together, both of the display and the touch panel are limited in size. Therefore, it is difficult to secure the area on which many characters to be inputted are displayed.
Before an input technology of Japanese kana characters is described, a typical example of a method for dividing all the forty-six kana characters into some groups is described. FIG. 27 illustrates a “kana syllabary” in which Japanese kana characters are arranged in a table format. In the kana syllabary shown in FIG. 27, all the kana characters are described using a combination of alphabetical characters, that is, “the Roman alphabet,” so that an arrangement thereof are easily recognized. “Columns” of “ (hereinafter referred to as “a”)-column” to “ (hereinafter referred to as “wa”)-column” mean groups in which forty-six kana characters are grouped according to presence or absence of a consonant and characters having a common consonant. In the kana syllabary shown in FIG. 27, the “column” is illustrated as longitudinally aligned characters. A total of ten “columns” exist, and each of the ten “columns” has a specific name, that is, “a ()-column,” “ (hereinafter referred to as “ka”)-column,” . . . . “wa ()-column” and the like. Characters belonging to the “a ()-column” include no consonant, but only a vowel. Characters belonging to “ka ()-column,” “ (hereinafter referred to as “sa”)-column,” “ (hereinafter referred to as “ta”)-column,” “ (hereinafter referred to as “na”)-column,” “ (hereinafter referred to as “ha”)-column,” “ (hereinafter referred to as “ma”)-column,” “ (hereinafter referred to as “ya”)-column,” and “ (hereinafter referred to as “ra”)-column” include consonants, “k,” “s,” “t,” “n,” “h,” “m,” “y,” and “r,” respectively, but the “wa ()-column” includes three characters “wa (),” “ (hereinafter referred to as “wo”),” and “ (hereinafter referred to as “n”)” other than characters belonging to the nine “columns” above described. Neither “wo ()” nor “n ()” include a consonant, but the “wa ()” and “n ()),” however, are included in the “wa ()”-column for convenience. “Rows” in “a ()-row,” “ (hereinafter referred to as “i”)-row,” “ (hereinafter referred to as “u”)-row,” “ (hereinafter referred to as “e”)-row,” and “ (hereinafter referred to as “o”)-row” mean groups in which forty-six kana characters are grouped according to characters having a common vowel. In the kana syllabary shown in FIG. 27, each of the “rows” is illustrated as transversely aligned characters. Vowels which the “a ()-row,” the “i ()-row,” the “u ()-row,” the “e ()-row,” and the “o ()-row” include, are “a (),” “i (),” “u (),” “e ()” and “o (),” respectively. In the “wa ()-column,” “wa ()” is assigned to a character of the “a ()-row,” “wo ()” is assigned to a character of the “o ()-row,” and “n ()” is regarded as an exception. As mentioned above, a part of a method for dividing into the “column” and “row” includes an exception. However, since the method for dividing into the “column” and “row” is not essential for the essence of the present invention, the exception can be neglected. Additionally, the method for dividing into the “column” and “row” described above is one of examples thereof.
As a way of coping with a problem of displaying many characters for selection, above-mentioned, a method is known, in which many characters are classified into a plurality of groups, and only character typifying each of the groups is displayed on the display. For example, with regard to a method for classifying Japanese kana characters, a method for classifying them into ten “columns” is commonly practiced. A character of “a ()-row,” which is a character typifying the “column,” is displayed on the display. For example, “a ()” is displayed on an input unit for inputting “a ()-column.” Characters to be inputted change, like “a ()”→“i ()”→“u ()”→“e ()”→“o (),” when the input unit on which “a ()” is displayed is repeatedly pushed down. The method above mentioned is used when a common keyboard besides the touch panel is used.
A method for inputting a character selected from many characters includes a method other than a method for changing, in order, a character to be inputted as above described. That is, when a key of “a ()” is pushed down once, “a (),” “i (),” “u (),” “e ()” and “o (),” which are other characters in the “a ()-row,” are displayed on a display unit as candidates to be selected. A character to be inputted is determined in the nominated characters for selection by a second selecting operation.
In a technology related to the information input device above-described, a kana character input device is known, which is described in Japanese Patent Application Laid-open No. 2000-112636 (hereinafter, referred to as “Patent document 1”). In the kana character input device, a plurality of characters are allocated to each of a plurality of keys of a touch panel or a keyboard. According to a selecting operation using the keys, and longitudinal and transverse moving directions of an operation point or an operation force after selection, one kana character is selected. Concretely, five kana characters are ordered and corresponded to each of the keys, and one kana character is selected among the five kana characters according to operated or pushed key and the direction of the operation or pushing down. In the kana character input device of Patent document 1, since five characters are allocated to one key, the number of keys for inputting characters is decreased significantly. Therefore, an area of the touch panel or the keyboard can be reduced, without reducing the size of the key. It is easy for a user to acquire a method for inputting characters, since the user can acquire an input operation by associating forty-six kana characters with groups to which five characters thereof are distributed.
A character input device described in Japanese Patent Application Laid-open No. 2006-178755 (Patent document 2) uses a method similar to the method for inputting kana characters of Patent document 1. In the character input device of Patent document 2, a kana character and a symbol are inputted by using keys for character input to which characters from “a ()-column” to “wa ()-column” are allocated and keys for symbol input. A contact detecting a push from a front face and contacts detecting a push from an upper side, a lower side, a left side and a right side are included in each key. Signals which correspond to five characters, that is, a character of “a ()-row” inputted from the front face and characters of “i ()-row,” “u ()-row,” “e ()-row,” and “o ()-row” which are inputted from four directions, that is, from the upper side, the lower side, the left side, and the right side, are outputted from each of the keys.
In a character input device described in Japanese Patent Application Laid-open No. 2003-157144 (Patent document 3), a hiragana input screen is displayed on a display unit. A CPU (Central Processing Unit) detects a contact state of a stylus pen on a display face of the display unit through a touch panel and a touch panel driver, and inputs a character based on the detection result. When the stylus pen makes contact, at a point, with a predetermined area on the touch panel facing a hiragana input key of the hiragana input screen, the CPU inputs a character which is allocated to the hiragana input key. When the stylus pen moves while making contact with the predetermined area on the touch panel facing the hiragana input key, the CPU inputs a different character according to a moving direction. Since a quite easy selection operation of the hiragana input key is carried out by the method mentioned above, many characters can be easily inputted.
In a kana input method using a liquid crystal touch panel described in Japanese Patent Application Laid-open No. 2002-222053 (Patent document 4), a group of characters for selection of characters to be inputted is superimposed on a screen of the liquid crystal touch panel. Initially, a character string, “a (),” “ka (),” “sa ()” “ta (),” “na (),” “ha (),” “ma ()” “ya (),” “ra (),” and “wa (),” consisting of characters in “a ()-row” of each “column” are transversely displayed in line. When a touch input on one character in the character string occurs, a character string, other than the “a ()-row,” of the “column” including the character at which the touch input occur, are longitudinally superimposed in line under the key on which the touch input is occurred. In this state, when a touch input on one character in the “column” longitudinally arranged in line occurs, the character is inputted.
In a character input method described in Japanese Patent Application Laid-open No. 2005-92441 (Patent document 5), ten characters in “a ()-row” of each column are displayed on a screen which is lotted on a touch panel. When a character is touched, characters in the “column” including the touched character are superimposed in line transversely or longitudinally. When a character to be inputted in the characters displayed in line is touched, the touched character is inputted.